Fire alarm apparatus



May 15, 1956 v. P. MULLALLY FIRE ALARM APPARATUS 2 Sheets-Sheet 1 FiledJuly 28, 1951 May 15, 1956 v. P. MULLALLY 2,745,926

FIRE ALARM APPARATUS Filed July 28, 1951 2 Sheets-Sheet 2 P f J f $5..$5 $5 gi. $5

United States Patent This invention relates to improvements in firealarm apparatus for signalling the occurrence of a fire within abuilding. More particularly it provides fire signalling apparatuswherein an electrically operated signal responds to a flash-consumptionof any of a suitable number of highly combustible circuit-controllingelements which have Wick-like runners along which a flame or sparkrapidly travels to ignite one of the highly combustiblecircuitcontrolling elements when a fire comes in contact with one of thewick-like runners.

It is among the objects of the invention to provide a fire alarmapparatus Whose alarm orsignal may be more promptly responsive to afireas compared with prior fire alarm-systems wherein the melting of fusiblemeans by heat developed by a fire is relied upon to set off the alarm orother warning signal. Whereas the mentioned prior fire alarm systemsinvolve substantial delays while a fire developssuflicie'ntly togenerate enough heat to melt at circuit-controlling fusible rn'eansbefore the system responds to sound an alarm or to give a visual signal, the apparatus of the invention responds on the prin- 'ciple ofconducting a fire to any of a suitable number of circuit-controllingelements which are of a combustible nature to be consumed in a flashwhen ignited. Wick-type runners extending from the circuit-controllingelements mayextend into or close to regions where combustible materialsare stored and into any other-regions where a fire might'originate, andeach runneris adapted to rapidly conduct a'flame or spark to acircuit-controlling element when anyp'ortion 'of its extent is contactedby a fire.

Another object of the invention is to provide a fire alarm apparatuswherein an electric signalling circuit or an auxiliary circuit has aplurality or multiplicity of circuit-controlling devices distributedalong the circuit interiorly of a building, each said device including acontrol means adapted to be quickly consumed when ignited, thereby toefiect a closing of a signalling circuit, there being at least onerelatively long wick-type runner extending from each said device alongwhich a flame or spark rapidly travels to ignite a said device when anyportion of a runner is contacted by fire. In one embodiment of theinvention, a plurality or multiplicity of normally closedcircuit-controlling devices are connected in parallel in a signallingcircuit, each held open by a readily combustible flash element fromwhich at least one Wick-type runner extends. In another embodiment aplurality or multiplicity of readily combustible flash devices aredistributed in series in an auxiliary circuit which is maintained closedso long as all of said devices continue intact, thereby maintaining asignalling circuit open, said auxiliary circuit being adapted to beopened if and when any of said devices becomes consumed by flame,thereby to efiect closing of the signalling circuit.

It is, moreover, my purpose and object generally to improve thestructure and operative efliciency of fire alarm systems and moreespecially to hasten the response of such systems by conducting a fireto the responsive ice means as distinguished from prior practices whichrely upon heat generated by a fire to melt a fusible -circuit-.

controlling means.

In the accompanying drawings:

Fig. l is a diagrammatic representation of a fire alarm system embodyingfeatures of the invention;

Fig. 2 is an elevational'view showing portionsof the system of Fig. 1supported below a floor of a building, the floor being shown incross-section;

Fig. 3 is a front elevation of one of the circuitcontrolling devices ofthe system of Figs. 1 and 2, on a largerscale;

Fig. 4 is a diagrammatic representation of a modified form of fire alarmsystem embodying features of the invention; and

Fig. 5 is an elevational view,with parts in cross-section, of 'one ofthe circuit-controlling devices of the Fig. '4 system.

Referring to the drawings, and more particularly to the embodiment ofthe invention as illustrated in Figs. l-3, the conductors 10, 12 maylead from any suitable source of electric current, they convenientlybeing a part of the usual v. house circuit,-assuming that the alarmsystem is to be installed in a home. A suitable reducing transformerisrepresented at 14, the low side of which is connected by theconductors 16, 18 and 20 to the two contacts 22, 24 of a solenoid switchwhich is indicated generally at 26. A signal device 28, which may be al-gong-or a light, or any other -signallingmeans, is connected inconductor 18, the circuit through 'thesignal device 28 being open at thecontacts 22, 24 in Fig. -1. A manual switch 30 in conductor 20permits-manual opening of'the signal circuit when the solenoid switch 26is closed.

An auxiliary circuit, provided by the conductors 16', 20!,leads throughthe coil 32 of the solenoid switch 26, and this auxiliary circuitnormally is energized holding the solenoid switch 26 in its opencondition of Fig. 1 against its biasing spring 34 which tends to closeit.

Thenormally closed auxiliary circuit, as represented in Fig. 1, has itsconductor 16 made up in 'part of a plurality or multiplicity ofrelatively short conductors 16 which are connected together by thecircuit-controlling devices 36.

"As best seen in Fig. '3, theadjacent end p'ortion's'of the shortconductors 16 are held in electrical contact by the circuit-controllingdevices 36, each of which latter is formed, at least in part, of ahighly combustible material which is adapted to be consumedsubstantially instantaneously when ignited, thereby to release theheldtogether end portions of the conductors 16 Conveniently, the devices36 may be relatively small and thin pieces of Celluloid or the like,each provided with a small hole 38 through which the adjacent endportions of two conductors 16 may be inserted with the walls of the holecrowding the conductors together and maintaining them in good electricalcontact. As shown in Fig. 3, the in serted end portion of each conductor16 may be turned back and twisted around an adjacent portion of the sameconductor to ensure that the conductor ends will not be pulled out ofthe hole 38. Each device 36 has extending from it a strip or string 40of combustible material which constitutes a wick-type runner along whicha flame or spark may run for igniting the device 36.

According to the invention, the conductors of the auxiliary circuits areto be mounted with the circuit-controlling devices 36 suitablydistributed over the area of a room, a cellar or storage region,preferably under a ceiling 42, in spaced relation thereto, as in Fig. 2,with the wick-type runners 40 extending down at any desired number oflocations. The runners may be as long or as short as may seem desirableunder particular conditions,

but each should be of a nature to quickly conduct a flame or spark forigniting the attached circuit-controlling device 36 if and when a flamecomes in contact with any part of the runner. In storage regions and incellars, the runners may hang down among the stored materials or Iobjects and around oil storage tanks, and the like. In

living quarters, oflices, and the like, the runners may beinconspicuously attached to the walls of the rooms, and a flame or sparkruns along the runners without themselves being the means of spreading afire.-

In the embodiment of Figs. 4 and 5, the auxiliary circuit is a normallyopen circuit which has circuit-controlling devices 44 connected inparallel therein, and the solenoid switch 26' is a normally open switchwhich closes in response to energization of its coil 32'. The devices 44may be of any suitable variety adapted to close the auxiliary circuit inresponse toconductance of a flame or spark thereto. Conveniently, eachdevice 44 may be a normally closed switch of a type illustrated in Fig.5 which is held open by a strip 46 of highly inflammable material whichmay be secured in depressing relation to the switch actuator 48, andwhich may have a wick-type runner 40 extending therefrom similar to therunners 40 in the Figs. 13 form.

Whereas the auxiliary circuit in the Figs. 1-3 embodiment is a closedcircuit which opens in response to igniting of any one of thecircuit-controlling devices 36, both the signalling and the auxiliarycircuits are open circuits in the Figs. 4 and 5 embodiment, theauxiliary circuit closing through the solenoid coil 32 in response toigniting of the strip 46 of any one of the circuit-controlling switchdevices 44.

It is intended that the patent shall cover, by suitable expression inthe appended claims, whatever features of patentable novelty exist inthe invention disclosed.

I claim as my invention:

1. In a fire alarm apparatus having an electric circuit with asignalling means therein and with a pair,of electrical contacts at eachof a plurality of distributed locations in said circuit at each of whichlocations the contacts are relatively movable to open and close saidcircuit thereby to control the operation of said signalling means, thecombination with each said pair of electrical contacts, of a body ofmaterial holding the pair of contacts in their condition wherein saidsignalling means is inoperative, said body of material at each said pairof electrical contacts being a relatively high melting point materialwhich continues stable in the presence of relatively high temperaturesbut which is highly inflammable and becomes consumed in a flash whencontacted by flame, thereby to release said pair of contacts forrelative movement to condition said electrical circuit for operation ofsaid signalling means, a said flash consumption of a said body ofmaterial leaving the conducting portions of said circuit intact forrestoration of its original condition by replacing the consumed body ofmaterial by another similar body of material in said holding relation tosaid pair of contacts, and a flame runner of highly inflammable materialconnected to said body of material at at least one of said pairs ofcontacts for conducting flame rapidly from a remote location to saidbody of contact-holding material to effect a said flash consumption ofsaid body of material.

2. In a fire alarm apparatus having an electric circuit with asignalling means therein and with a pair of electrical contacts at eachof a plurality of distributed locations in said circuit at each of whichlocations the contacts are relatively movable to open and close saidcircuit thereby to control the operation of said signalling means, thecombination with each said pair of electrical contacts, of a body ofmaterial'holding the pair of contacts in their condition wherein saidsignalling means is inoperative, said body of material at each said pairof electrical contacts continuing stable in the'presence of relativelyhigh temperatures but beingrhighly inflammable for consumption in aflash when contacted by flame, thereby to release said pair of contactsfor relative movement to condition said electrical circuit for operationof said signalling means, a said flash consumptionot a said body ofmaterial leaving all conducting portions of said circuit intact forrestoration of its original condition by replacing the consumed body ofmaterial by another similar body of material in said holding relation tosaid pair of contacts.

References Cited in the file of this patent UNITED STATES PATENTSStrange June 5,

